PHARMACOKINETIC BEHAVIOR OF FENBENDAZOLE IN BUFFALO AND CATTLE

Concentrations of fenbendazole and of drug metabolites in plasma were measured in buffalo and cross-bred cattle after single intraruminal ad ministration at two different doses. Plasma concentrations of the pare nt compound fenbendazole and the two metabolites, viz. oxfendazole and fenbendazole sulfone, were much lower in buffalo compared with cattle , at a dose of 7.5 mg/kg body weight as indicated by lower area under concentration curve and concentration maximum. At a dose of 15 mg/kg b ody weight there were corresponding increases in plasma metabolite con centrations in cattle. However, buffaloes did not show a similar corre sponding increase.